Early life conditions and adolescent sexual orientation: A prospective birth cohort study.

Abstract

This study tested the association between multiple prenatal and postnatal early life factors and adolescent sexual orientation in a longitudinal birth cohort. Factors included birthweight, gestational age, parental ages at birth, number of older brothers and sisters, breastfeeding, maternal anxiety/depression, family socioeconomic position, parent-child relationships, parental absences, pubertal body mass index, and housing issues. We used data on 5007 youth from the Avon Longitudinal Study of Parents and Children (ALSPAC). Sexual orientation was assessed using a 5-point scale of sexual attraction at 15.5 years. Early life factors were separated into three developmental periods: prenatal (n = 9), before 7 years (n = 5), and after 7 years (n = 5). We controlled for childhood gender nonconformity (GNCB), handedness, and digit ratio as markers of prenatal androgen exposure. GNCB was strongly associated with later male and female nonheterosexuality, and higher right-hand digit ratio was associated with later male nonheterosexuality. Boys with low birthweight and shorter breastfeeding duration were more likely to have a later nonheterosexual orientation. Boys with parental absence before 7 years of age were more likely to be nonheterosexual, but this effect disappeared after entering all early life history factors. Parental absence since birth, low prenatal family socioeconomic position, and poorer parent-child relationship were associated with later nonheterosexuality among girls. The results are discussed in the context of a life history framework for understanding human sexual orientation development in males and females.

Determinants of early sexual initiation among female youth in Ethiopia: A multilevel analysis of 2016 Ethiopian Demographic and Health Survey

“…It was also in agreement with studies conducted in Mexico (4), Philippines (17), Korea (42) and Canada (43). This might be due to the nature of substances to affect individual consciousness and critical thinking about the risk and consequences of early sexual initiation (15,22,24,25,44). Moreover, substance users are more subjected to causal sex and they may use it as a means of income for their addiction.…”

“…Furthermore, education may bring a behavioral change towards the reduction of risk factors like, substance use which may expose them to early sexual initiation (40). Moreover, parent-youth communication and supervision might be good for youth who are educated (13,14,22,25,41).…”

Determinants of early sexual initiation among female youth in Ethiopia: a multilevel analysis of 2016 Ethiopian Demographic and Health Survey

“…Early sexual initiation has negative health, social and economic consequences for both the women and feature generation. It was a risk factor for sexually transmitted infections including HIV/AIDS [16][17][18][19], unsafe sexual practice [8,9,20], unwanted pregnancy [18,[21][22][23], mental problem and maternal death [16,18,24,25]. It also increased the risk of school dropout, poor school performance, stigma and discrimination [26][27][28].…”

Male Homosexual Preference: Femininity and the Older Brother Effect in Indonesia

“…For example, birth weight is lower for newborn males with older brothers, but not for newborn females with older brothers or older sisters (Côté, Blanchard, & Lalumière, 2003). The higher influence of previous brothers to reduce male birth-weight, compared to female birth-weight, has been repeated in large samples (e.g., Nielsen et al, 2008) and is consistent with a lower birth weight of homosexual men relatively to heterosexuals (Xu, Norton, & Rahman, 2019).…”